Diabetic retinopathy is known to be associated with a number of epigenetic markers, including methylation of the superoxide dismutase 2 (Sod2) and matrix metalloproteinase-9 (MMP-9) genes, an increase in transcription of Lysine-specific histone demethylase 1 (LSD1), a H3K4 and H3K9 demethylase, and various DNA Methyl-Transferases (DNMTs), and increased presence of microrubonucleic acids (miRNAs) for transcription factors [15,16]. The gene discussed is SOD2; the disease is diabetic retinopathy.